1. Field of the Invention
The present invention relates to a wrap spring clutch, especially for arrangement in the drive train of a motor vehicle. Such a clutch includes a first component rotatable around a rotary axis, a second component rotatable around the rotary axis, and a wrap spring arrangement held on one of the two components in a substantially rotation-proof fashion relative thereto.
2. Discussion of the Prior Art
Such wrap spring clutches are known from the prior art, in particular, for use in the drive train of motor vehicles. These clutches generally have a first component in the form of an input part connected to the crank shaft of an internal combustion engine. The first component further comprises a centrifugal mass part as well as a housing, which, in areas, surrounds the clutch arrangement. A second component of the wrap spring clutch is held in rotation-proof fashion on a gear input shaft. The second component comprises a part embodied substantially cylindrically. The cylindrical circumferential surface of the second component is surrounded by a wrap spring wound in coil-like fashion. The wrap spring, at its first end, is secured to the first component by a bolt or the like. At its second end, the wrap spring interacts with a disengagement lever, located on the housing, that can be pivoted around an axis approximately parallel to the rotary axis of the wrap spring clutch. When the disengagement lever is in a non-pressurized position, the wrap spring contracts and produces a normal force on the cylindrical outer surface of the second component. This normal force is reinforced by a self-locking effect that occurs during torque transmission.
In this known wrap spring clutch, the problem exists that the interaction area of the wrap spring with the second component extends over substantially the entire circumferential surface of the second component and is thus relatively large, whereas the wrap spring is securely connected to the first component only by means of the attachment bolt. This means that high loads can occur during torque transmission, particularly in the connection area, which can in turn lead to damage in this area in the event of relatively large torque fluctuations or impacts.